Note 11 - Segment Reporting - Segment Information (Details) - USD ($)	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018	Dec. 31, 2018
Assets	$ 50,628,417	$ 60,641,000	$ 52,514,562
Revenue	3,468,675	9,153,833
Operating income/(loss)	(2,565,102)	910,568
Pretax income/(loss)	(2,632,947)	806,174
Intersegment Eliminations [Member]
Assets	(9,000)	(9,000)
Revenue	(66,000)	(183,000)
Operating income/(loss)	(1,001,000)	(1,019,000)
Pretax income/(loss)	(1,002,000)	(1,019,000)
CVD [Member] | Operating Segments [Member]
Assets	38,604,000	47,397,000
Revenue	2,019,000	6,705,000
Operating income/(loss)	(1,540,000)	1,515,000
Pretax income/(loss)	(1,511,000)	1,624,000
SDC [Member] | Operating Segments [Member]
Assets	5,182,000	6,463,000
Revenue	1,087,000	2,260,000
Operating income/(loss)	174,000	718,000
Pretax income/(loss)	176,000	718,000
Materials [Member] | Operating Segments [Member]
Assets	6,851,000	6,790,000
Revenue	429,000	372,000
Operating income/(loss)	(198,000)	(303,000)
Pretax income/(loss)	$ (296,000)	$ (517,000)